Electrode assembly manufacturing equipment, electrode assembly manufacturing method, and electrode assembly

Abstract

The present application provides roll-to-roll type electrode assembly manufacturing equipment comprising: a sheet supply unit (100) including a first sheet supply unit for supplying a first separator sheet and a second separator sheet and a second sheet supply unit for supplying a lithium metal sheet; an application unit for applying a binder to at least one of the first separator sheet and the second separator sheet; and a lamination unit for laminating the first separator sheet and the second separator sheet while having the lithium metal sheet disposed therebetween, wherein: each of the first separator sheet and the second separator sheet includes an inner area corresponding to the lithium metal sheet at the time of lamination by the lamination unit, and an outer area at least partially surrounding the peripheral portion of the inner area in the thickness direction (TD); and the application unit applies the binder onto at least a part of the outer area of the first separator sheet and the outer area of the second separator sheet.

Description

Electrode assembly manufacturing equipment, electrode assembly manufacturing method, and electrode assembly

[0001] Cross-citation with related applications

[0002] This application is based on and claims the benefit of priority from Korean Patent Application Nos. 10-2024-0038053 and 10-2024-0056612, filed with the Korean Intellectual Property Office on March 19, 2024 and April 29, 2024, respectively, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present application relates to a manufacturing facility for manufacturing an electrode assembly, a method for manufacturing an electrode assembly, and an electrode assembly.

[0005] Recently, demand for mobile devices such as smartphones, tablet PCs, and wireless earphones has been increasing. Furthermore, with the development of electric vehicles, energy storage batteries, robots, and satellites in full swing, research is actively underway on high-performance secondary batteries capable of repeated charging and discharging as an energy source.

[0006] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries offer the advantages of virtually no memory effect compared to nickel-based batteries, allowing for easy charging and discharging, a very low self-discharge rate, and high energy density.

[0007] Meanwhile, lithium metal batteries sometimes use lithium metal as the anode. While lithium metal is advantageous for increasing the battery's energy density, it is more difficult to handle due to its softness and tendency to stick compared to the previously used copper (Cu).

[0008] The present application can provide an electrode assembly manufacturing facility that, taking into account the soft and sticky characteristics of lithium metal, positions lithium metal between separators to laminate them while preventing the laminate from separating during high-speed operation, thereby improving stability. The present application can provide an electrode assembly manufacturing facility that improves productivity by preventing alignment problems even when the tension applied to a sheet is not maintained or is distorted due to meandering during high-speed operation in a roll-to-roll method. The present application can provide an electrode assembly manufacturing facility that manufactures an electrode assembly that minimizes short-circuit problems during battery operation by preventing lithium metal from growing in the direction of lamination. The present application can provide a method for manufacturing an electrode assembly using the electrode assembly manufacturing facility, and can provide an electrode assembly manufactured through the electrode assembly manufacturing facility.

[0009] According to one embodiment of the present application, a roll-to-roll electrode assembly manufacturing facility comprises: a sheet supply unit including a first sheet supply unit for supplying a first separator sheet and a second separator sheet and a second sheet supply unit for supplying a lithium metal sheet; an application unit for applying a binder to at least one of the first separator sheet and the second separator sheet; and a lamination unit for laminating the first separator sheet and the second separator sheet with the lithium metal sheet therebetween, wherein each of the first separator sheet and the second separator sheet includes an inner region corresponding to the lithium metal sheet and an outer region at least partially surrounding an outer region of the inner region in a width direction (TD) when laminating by the lamination unit, and the application unit can apply the binder to at least a part of the outer region of the first separator sheet and the outer region of the second separator sheet.

[0010] In an electrode assembly manufacturing facility according to one embodiment of the present application, the first separator sheet and the second separator sheet can be mutually bonded based on the adhesive strength of the applied binder.

[0011] In an electrode assembly manufacturing facility according to one embodiment of the present application, the application unit may apply the binder to an inner region of the first separator sheet and an inner region of the second separator sheet.

[0012] In an electrode assembly manufacturing facility according to one embodiment of the present application, each of the outer region of the first separator sheet and the outer region of the second separator sheet includes a first outer region adjacent to a first outer boundary in the width direction (TD) of the lithium metal sheet and a second outer region adjacent to a second outer boundary in the width direction (TD) of the lithium metal sheet, and the application unit may apply a binder to either the first outer region of the first separator sheet or the first outer region of the second separator sheet; and either the second outer region of the first separator sheet or the second outer region of the second separator sheet.

[0013] In an electrode assembly manufacturing facility according to one embodiment of the present application, the laminating unit may laminate the first separator sheet and the second separator sheet with the lithium metal sheet interposed therebetween, such that one surface of the lithium metal sheet faces the inner region of the first separator sheet and the other surface of the lithium metal sheet faces the inner region of the second separator sheet, and the applying unit may continuously or partially apply the binder to at least a portion of the outer region of the first separator sheet and the outer region of the second separator sheet.

[0014] In an electrode assembly manufacturing facility according to one embodiment of the present application, the bonding part may include a pair of guide rollers spaced apart by a predetermined gap.

[0015] In an electrode assembly manufacturing facility according to one embodiment of the present application, the bonding unit may bond the lithium metal sheet by interposing it between the first separator sheet and the second separator sheet so that, during bonding, the pair of guide rollers contact the first separator sheet and the second separator sheet, respectively, but do not contact the lithium metal sheet.

[0016] In an electrode assembly manufacturing facility according to one embodiment of the present application, each of the outer region of the first separator sheet and the outer region of the second separator sheet includes a first outer region adjacent to a first outer boundary in the width direction (TD) of the lithium metal sheet and a second outer region adjacent to a second outer boundary in the width direction (TD) of the lithium metal sheet, and each of the pair of guide rollers may include a first member pressing the first outer region of each of the first separator sheet and the second separator sheet; a second member pressing the second outer region of each of the first separator sheet and the second separator sheet; and a connecting member connecting the first member and the second member.

[0017] In an electrode assembly manufacturing facility according to one embodiment of the present application, the first member, the second member, and the connecting member may each have a cylindrical shape.

[0018] In an electrode assembly manufacturing facility according to one embodiment of the present application, the bottom outer diameter (r3) of the connecting member may be smaller than the bottom outer diameter (r1) of the first member and the bottom outer diameter (r2) of the second member.

[0019] In an electrode assembly manufacturing facility according to one embodiment of the present application, the first member and the second member may be arranged to rotate around the same rotational axis.

[0020] In an electrode assembly manufacturing facility according to one embodiment of the present application, the center of the bottom surface of the connecting member may be located on the rotational axis of the first member and the second member.

[0021] In an electrode assembly manufacturing facility according to one embodiment of the present application, the width direction (TD) length of the first outer region (OA_1) of the first separator sheet and the second separator sheet may be less than or equal to the width direction (TD) length of the second outer region (OA_2) of the first separator sheet and the second separator sheet, and the thickness (w2) of the second member may be less than or equal to the width direction (TD) length of the second outer region (OA_2) of the first separator sheet and the second separator sheet.

[0022] In an electrode assembly manufacturing facility according to one embodiment of the present application, the thickness (w3) of the connecting member may be equal to or greater than the length (ML_TDw) in the width direction (TD) of the lithium metal sheet.

[0023] A method for manufacturing an electrode assembly according to one embodiment of the present application includes the steps of: preparing a first separator sheet, a second separator sheet, and a lithium metal sheet in a roll form; applying a binder to a portion of at least one of the first separator sheet and the second separator sheet; and laminating the first separator sheet and the second separator sheet with the lithium metal sheet therebetween to form an anode structure, wherein the step of applying the binder may include the step of applying the binder to an outer region that at least partially surrounds an inner region corresponding to the lithium metal sheet in a width direction (TD) of at least one of the first separator sheet and the second separator sheet when laminating.

[0024] In a method for manufacturing an electrode assembly according to one embodiment of the present application, a step of stacking an anode on the formed anode structure and folding the anode structure in the width direction to surround the anode, thereby alternately and sequentially stacking the anode structure and the anode, may be further included.

[0025] An electrode assembly according to one embodiment of the present application includes a positive electrode, a negative electrode, and a separator, wherein the negative electrode includes lithium metal and is interposed between two separators to form a negative electrode structure, wherein the negative electrode structure includes a plurality of stacked portions and a plurality of folded portions, wherein the electrode assembly has a structure in which the stacked portions of the negative electrode structure and the positive electrode are alternately and sequentially stacked, wherein the two separators are formed to protrude at least partially in the width direction from the lithium metal, and wherein at least a part of the protruding portions of the two separators can be mutually bonded by a binder with the lithium metal therebetween.

[0026] In an electrode assembly according to one embodiment of the present application, the positive electrode includes a positive electrode active material layer including a positive electrode active material and a positive electrode current collector supporting the positive electrode active material layer, and the positive electrode active material may include a sulfur compound.

[0027] The present application considers the softness and easy occurrence of lithium metal separator phenomenon, and thus improves stability by positioning lithium metal between separators and bonding them together, while preventing the bonding from separating during high-speed operation. The present application can improve productivity by preventing alignment problems even when the tension applied to the sheet is not maintained or the sheet becomes warped due to meandering during high-speed operation in a roll-to-roll method. The present application can manufacture an electrode assembly that minimizes short-circuit problems during battery operation by preventing dendrite growth in the direction in which the lithium metal is bonded.

[0028] The drawings shown in this application are according to an embodiment of this application, and the ratio of the width, width, or thickness (or height) of each component is for the purpose of explaining this application in detail, and these ratios may differ from the actual ones. In addition, in the coordinate system shown in the drawings, each axis may be perpendicular to each other, and the direction pointed by the arrow may be the + direction, and the direction opposite to the direction pointed by the arrow (the direction rotated by 180 degrees) may be the - direction.

[0029] FIG. 1 is a plan view illustrating at least a portion of an electrode assembly manufacturing facility according to an embodiment of the present application.

[0030] FIG. 2, FIG. 3 and FIG. 4 are plan views showing the position and method of applying a binder onto a separator sheet by an application unit according to an embodiment of the present application.

[0031] FIG. 5 is a plan view showing an application unit and a position where the application unit applies a binder onto a separator sheet according to an embodiment of the present application.

[0032] FIG. 6 is a perspective view illustrating a separator sheet and a lithium metal sheet moving along the direction of travel (MD) in an electrode assembly manufacturing facility according to an embodiment of the present application.

[0033] FIG. 7, FIG. 8 and FIG. 9 are plan views showing the positional relationship of a separator sheet and a lithium metal sheet in an electrode assembly manufacturing facility according to an embodiment of the present application.

[0034] FIG. 10 is a perspective view showing at least a portion of a joint according to an embodiment of the present application.

[0035] FIG. 11 is a perspective view illustrating at least a portion of a guide roller according to an embodiment of the present application.

[0036] FIG. 12 is a plan view illustrating at least a portion of a guide roller according to an embodiment of the present application.

[0037] FIG. 13 is a perspective view illustrating at least a portion of a joint according to an embodiment of the present application.

[0038] FIG. 14 is a plan view illustrating at least a portion of a cathode structure according to an embodiment of the present application.

[0039] FIG. 15 is a plan view illustrating at least a portion of an electrode assembly according to an embodiment of the present application.

[0040] Before proceeding with a detailed description of this application, it should be noted that terms and words used in this specification and claims may not be interpreted solely based on their conventional or dictionary meanings. Furthermore, inventors should interpret terms and concepts in a way that aligns with the technical concept of this application, based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention. The embodiments described in this specification and the configurations depicted in the drawings represent only the most preferred embodiments of this application and may not represent the entire technical concept of this application. Therefore, various equivalents and variations may exist at the time of filing of this application.

[0041] The same reference numbers or symbols in each drawing attached to this specification may indicate parts or components that perform substantially the same functions. For convenience of explanation and understanding, the same reference numbers or symbols may be used in different embodiments. In other words, even if components with the same reference numbers are depicted in multiple drawings, they may not all represent a single embodiment.

[0042] In the following description, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprise" or "comprises" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but are to be understood as not excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0043] In addition, in the description below, expressions such as upper, upper, lower, lower, side, front, and rear are expressed based on the direction shown in the drawing, and may be expressed differently if the direction of the object is changed.

[0044] Additionally, terms including ordinal numbers, such as "first," "second," etc., may be used in this specification and claims to distinguish between components. These ordinal numbers may be used to distinguish identical or similar components from each other, and the use of these ordinal numbers should not be interpreted in a limited manner. For example, components associated with these ordinals should not be interpreted in a restricted manner, such as in the order of use or arrangement, based on their numbers. If necessary, each ordinal number may be used interchangeably.

[0045] In this specification, the term "battery" may be used interchangeably with "cell." Furthermore, the terms "battery" and "cell" may collectively refer to a battery cell, which is a unit thereof, or a battery module or battery pack containing a battery cell.

[0046] The present application considers the soft and brittle nature of lithium metal, and positions lithium metal between separators to bond them together, while preventing the bond from separating during high-speed operations, thereby improving stability. The present application can improve productivity by preventing alignment problems even when the tension applied to the sheet is not maintained or the sheet becomes warped due to meandering during high-speed operations in a roll-to-roll method. The present application can manufacture an electrode assembly that minimizes short-circuit problems during battery operation by preventing the lithium metal from growing in the bonded direction.

[0047] FIG. 1 is a plan view illustrating at least a portion of an electrode assembly manufacturing facility (10) according to an embodiment of the present application.

[0048] The electrode assembly manufacturing facility (10) can perform at least some of its processes using a roll-to-roll method. The roll-to-roll process is a continuous process that processes sheet-shaped materials by applying tension to them using rollers (R) to give them new functions. The roll-to-roll process can be advantageous for mass production because it continuously processes materials.

[0049] The electrode assembly manufacturing equipment (10) can position a lithium metal sheet (ML) between a plurality of separator sheets (111S, 112S) and manufacture a negative electrode structure (400) by bonding the plurality of separator sheets (111S, 112S) (see FIG. 14).

[0050] In this specification, the separator sheet may mean a membrane formed in the form of a sheet to prevent electrical short circuit between the cathode and the anode in a battery cell and to allow electron transport substances to pass through. Here, the electron transport substance may be, for example, lithium ions (Li). + ), sodium ions (Na + ) or potassium ions (K +) may be.

[0051] The plurality of separator sheets (111S, 112S) are not particularly limited as long as they are used in the art, and it is preferable that they have low resistance to ion movement of the electrolyte and excellent wettability of the electrolyte (particularly, electrolyte solution). The plurality of separator sheets (111S, 112S) may each independently be a porous polymer film, for example, a porous polymer film made of a polyolefin material such as an ethylene polymer, a propylene polymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, or an ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof.

[0052] The electrode assembly manufacturing equipment (10) may include a sheet supply unit (100) that supplies a plurality of separator sheets (e.g., a first separator sheet (111S), a second separator sheet (112S)) and a lithium metal sheet (ML), a coating unit (200, see FIGS. 2 to 5) that applies a binder (B), and a laminating unit (300) that laminates the plurality of separator sheets (111S, 112S) with the lithium metal sheet (ML) therebetween. Although not all are shown in the drawings, the plurality of separator sheets (111S, 112S) and the lithium metal sheet (ML) may be provided with an appropriate tension without sagging by rollers (R) provided at appropriate locations. In one example, the sheet supply unit (100) may continuously supply at least one of the plurality of separator sheets (e.g., the first separator sheet (111S), the second separator sheet (112S)) and the lithium metal sheet (ML) in a roll form. In this specification, continuously supplied may mean that at least some areas are supplied without interruption.

[0053] In order for the electrode assembly manufacturing equipment (10) to continuously manufacture anode structures (400) of similar quality, it is advantageous for a plurality of separator sheets (111S, 112S) and lithium metal sheets (ML) to be laminated while maintaining appropriate tension and with the margin portions (e.g., the outer area in the width direction) aligned. However, when working at high speed in a roll-to-roll manner, problems such as tension changes in at least some areas or alignment misalignment due to meandering may occur. In particular, misalignment can be considered an alignment problem.

[0054] The electrode assembly manufacturing equipment (10) can improve productivity by applying a binder (B) to some areas of a plurality of separator sheets (111S, 112S) and bonding the plurality of separator sheets (111S, 112S) to each other based on the adhesive strength of the applied binder (B), thereby preventing alignment problems while preventing separation of the bonding between the separator sheets (111S, 112S) during high-speed operation.

[0055] In this specification, the binder (B) is not particularly limited in type, as long as it exhibits adhesive performance on its own or through thermal curing or photocuring, etc., and does not undergo a physical or chemical reaction with substances present in the battery cell. The binder (B) may include, for example, an acrylic resin, a urethane resin, an epoxy resin, or a silicone resin, which are generally known to be usable as adhesives.

[0056] The sheet supply unit (100) may include a first sheet supply unit (110) that supplies a first separator sheet (111S) and a second separator sheet (112S). The first sheet supply unit (110) may include a 1-1 sheet supply unit (111) that supplies the first separator sheet (111S) and a 1-2 sheet supply unit (112) that supplies the second separator sheet (112S). The first sheet supply unit (110) may additionally supply separator sheets in addition to the first separator sheet (111S) and the second separator sheet (112S). In one example, the 1-1 sheet supply unit (111) may continuously supply the first separator sheet (111S) in a roll form. In one example, the 1-2 sheet supply unit (112) may continuously supply the second separator sheet (112S) in a roll form.

[0057] The sheet supply unit (100) may include a second sheet supply unit (120) that supplies lithium metal sheets (ML). The speeds at which the first sheet supply unit (110) and the second sheet supply unit (120) supply the separator sheets (111S, 112S) and the lithium metal sheets (ML) may be set to be the same to prevent alignment problems. In one example, the second sheet supply unit (120) may continuously supply the lithium metal sheets (ML) in a roll form.

[0058] The sheet supply unit (100) is a device that can supply a plurality of separator sheets (111S, 112S) and lithium metal sheets (ML) at a constant rate, and may include, for example, a conveyor belt. In addition, the sheet supply unit (100) may set a predetermined path so that the plurality of separator sheets (111S, 112S) and lithium metal sheets (ML) can meet at the joining unit (300) described later. In the present specification, the direction of the path along which the sheet supply unit (100) moves each sheet may be referred to as a moving direction (MD).

[0059] The application unit (200) can apply a binder (B) to at least one of the first separator sheet (111S) and the second separator sheet (112S). For example, the electrode assembly manufacturing equipment (10) may include a plurality of application units (200) to apply the binder (B) to predetermined positions.

[0060] FIG. 2, FIG. 3 and FIG. 4 are plan views illustrating the position and method of applying a binder (B) on a separator sheet (111S) by an application unit (200) according to an embodiment of the present application. FIG. 5 is a plan view illustrating the position and method of applying a binder (B) on a separator sheet (111S) by an application unit (200) according to an embodiment of the present application. For details regarding the position and method of applying a binder (B) on another separator sheet (112S), reference may be made to the description below.

[0061] Fig. 6 is a perspective view illustrating a state in which a separator sheet (111S, 112S) and a lithium metal sheet (ML) move along a moving direction (MD) in an electrode assembly manufacturing facility (10) according to an embodiment of the present application. Figs. 7, 8 and 9 are plan views illustrating the positional relationship of a separator sheet (111S, 112S) and a lithium metal sheet (ML) in an electrode assembly manufacturing facility (10) according to an embodiment of the present application.

[0062] The application unit (200) can apply a binder (B) to at least one of the first separation membrane sheet (111S) and the second separation membrane sheet (112S) moved by the sheet supply unit (100). The speed at which the sheet supply unit (100) supplies the first separation membrane sheet (111S) and the second separation membrane sheet (112S) can be determined by considering the viscosity of the binder (B) and the binder (B) discharge speed of the application unit (200). The first separation membrane sheet (111S) and the second separation membrane sheet (112S) can be mutually bonded based on the applied binder (B), and this can be performed in the bonding unit (300) described later.

[0063] The structure of the application unit (200) is not particularly limited, but may include an injection unit (210) for receiving a binder (B), a storage unit (220) for storing the binder (B) received from the injection unit (210), and a discharge unit (230) for discharging the binder (B) stored in the storage unit (220) to the outside. In addition, the application unit (200) may further include a pump for smooth injection and discharge of the binder (B), and the binder (B) may be smoothly introduced into the storage unit (220) through the injection unit (210) or smoothly discharged to the outside through the discharge unit (230) by the force applied by the pump. In addition, the application unit (200) may further include an opening / closing unit that opens / closes between the storage unit (220) and the discharge unit (230), and the opening / closing unit may further include an element that can be controlled according to an electric signal to pattern the binder (B) applied to the first separation membrane sheet (111S) or the second separation membrane sheet (112S).

[0064] The application unit (200) can apply a binder (B) to at least one of a portion of the first separator sheet (111S) and a portion of the second separator sheet (112S). Each of the first separator sheet (111S) and the second separator sheet (112S) can include an inner region (IA) corresponding to the lithium metal sheet (ML) when combined by the combination unit (300) and an outer region (OA) that at least partially surrounds the outer portion of the inner region (IA) in the transverse direction (TD). The transverse direction (TD) can be perpendicular to the traveling direction (MD).

[0065] Here, the application unit (200) can apply the binder (B) to at least a portion of the outer area (OA) of the first separator sheet (111S) and the outer area (OA) of the second separator sheet (112S). In addition, the application unit (200) can not apply the binder (B) to the inner area (IA) of the first separator sheet (111S) and the inner area (IA) of the second separator sheet (112S).

[0066] The method by which the application unit (200) applies the binder (B) is not particularly limited. For example, the application unit (200) may apply the binder (B) continuously or partially to at least a portion of the outer area (OA) of the first separator sheet (111S) and the outer area (OA) of the second separator sheet (112S). Referring to FIG. 2, the application unit (200) may apply the binder (B) continuously. Referring to FIGS. 3 and 4, the application unit (200) may apply the binder (B) partially. The application unit (200) may implement a method of applying the binder (B) through the aforementioned opening and closing unit, for example.

[0067] Each of the outer region (OA) of the first separator sheet (111S) and the outer region (OA) of the second separator sheet (112S) may include a first outer region (OA_1) adjacent to a first outer boundary (ML_O1) in the width direction (TD) of the lithium metal sheet (ML) and a second outer region (OA_2) adjacent to a second outer boundary (ML_O2) in the width direction (TD) of the lithium metal sheet (ML). The first outer boundary (ML_O1) in the width direction (TD) of the lithium metal sheet (ML) may be located on the opposite side of the second outer boundary (ML_O2).

[0068] The application unit (200) can apply the binder (B) to at least one of the first outer region (OA_1) of the first separator sheet (111S) and the first outer region (OA_1) of the second separator sheet (112S) and at least one of the second outer region (OA_2) of the first separator sheet (111S) and the second outer region (OA_2) of the second separator sheet (112S). That is, the application unit (200) can apply the binder (B) so that it is appropriately positioned so that the first separator sheet (111S) and the second separator sheet (112S) are joined at the outer region (OA).

[0069] For example, referring to FIG. 7, the application unit (200) can apply the binder (B) to both the first outer area (OA_1) and the second outer area (OA_2) of the first separator sheet (111S), and can apply the binder (B) only to the second outer area (OA_2) of the second separator sheet (112S).

[0070] In addition, referring to FIG. 8, the application unit (200) may apply the binder (B) to both the first outer region (OA_1) and the second outer region (OA_2) of the first separator sheet (111S), and may not apply the binder (B) to the second separator sheet (112S). Alternatively, as another example, the application unit (200) may not apply the binder (B) to the first separator sheet (111S), and may apply the binder (B) to both the first outer region (OA_1) and the second outer region (OA_2) of the second separator sheet (112S). Even if the binder (B) is applied in this way, there is no problem in bonding the first separator sheet (111S) and the second separator sheet (112S) to each other based on the binder (B).

[0071] In addition, referring to FIG. 9, the application unit (200) may apply the binder (B) only to the first outer area (OA_1) of the first separator sheet (111S) and the second outer area (OA_2) of the second separator sheet (112S). Or, conversely, the application unit (200) may apply the binder (B) only to the second outer area (OA_2) of the first separator sheet (111S) and the first outer area (OA_2) of the second separator sheet (112S).

[0072] In addition, although not shown, the application unit (200) can apply the binder (B) to each of the first outer region (OA_1) and the second outer region (OA_2) of the first separator sheet (111S) and the first outer region (OA_1) and the second outer region (OA_2) of the second separator sheet (112S), and application of the binder (B) to only one of these regions can be omitted.

[0073] Fig. 10 is a perspective view illustrating at least a portion of a joining part (300) according to an embodiment of the present application. Fig. 11 is a perspective view illustrating at least a portion of a guide roller (310) according to an embodiment of the present application. Fig. 12 is a plan view illustrating at least a portion of a guide roller (310) according to an embodiment of the present application. Fig. 13 is a perspective view illustrating at least a portion of a joining part (300) according to an embodiment of the present application.

[0074] The bonding unit (300) can bond the first separator sheet (111S) and the second separator sheet (112S) with a lithium metal sheet (ML) therebetween. Specifically, the bonding unit (300) can bond the first separator sheet (111S) and the second separator sheet (112S) with a lithium metal sheet (ML) therebetween, such that one surface of the lithium metal sheet (ML) faces the inner area (IA) of the first separator sheet (111S) and the other surface of the lithium metal sheet (ML) faces the inner area (IA) of the second separator sheet (112S). The bonding unit (300) includes, for example, a pair of guide rollers (310) spaced apart by a predetermined gap, and bonding can be implemented using the pair of guide rollers (310).

[0075] Referring to FIG. 10, a pair of guide rollers (310) may be spaced apart by a predetermined gap, and the gap may be such that the first separator sheet (111S), the lithium metal sheet (ML), and the second separator sheet (112S) can all pass through, while a portion of the first separator sheet (111S) and a portion of the second separator sheet (112S) can come into contact with each other by the pressing force of the pair of guide rollers (310).

[0076] The joining unit (300) can be joined by interposing a lithium metal sheet (ML) between the first separator sheet (111S) and the second separator sheet (112S) so that, during joining, a pair of guide rollers (310) contact the first separator sheet (111S) and the second separator sheet (112S), respectively, but not contact the lithium metal sheet (ML). At this time, the first separator sheet (111S) can contact one surface of the lithium metal sheet (ML), and the second separator sheet (112S) can contact the other surface of the lithium metal sheet (ML).

[0077] Each of the pair of guide rollers (310) may include a first member (311) for pressing a first outer area (OA_1) of each of the first separator sheet (111S) and the second separator sheet (112S), a second member (312) for pressing a second outer area (OA_2) of each of the first separator sheet (111S) and the second separator sheet (112S), and a connecting member (313) for connecting the first member (311) and the second member (312). Since the first member (311) and the second member (312) of each of a pair of guide rollers (310) press the first separator sheet (111S) and the second separator sheet (112S) at positions corresponding to the first outer region (OA_1) and the second outer region (OA_2), the first separator sheet (111S) and the second separator sheet (112S) can be mutually bonded by the adhesive force of the binder (B) applied to these regions.

[0078] Meanwhile, the connecting member (313) passes through a position corresponding to the inner area (IA) of each of the first separator sheet (111S) and the second separator sheet (112S) and may or may not pressurize the inner area (IA).

[0079] The first member (311), the second member (312), and the connecting member (313) may each have a cylindrical shape. The cylindrical shape includes a circular bottom and a square side. Only the first separator sheet (111S) and the second separator sheet (112S) pass between the first member (311) and the second member (312) of the pair of guide rollers (310), but the first separator sheet (111S), the second separator sheet (112S), and the lithium metal sheet (ML) may pass between the connecting members (313). Therefore, for uniform bonding, the bottom outer diameter (r3) of the connecting member (313) may be smaller than the bottom outer diameter (r1) of the first member (311) and the bottom outer diameter (r2) of the second member (312).

[0080] Meanwhile, for uniform bonding, the bottom outer diameter (r1) of the first member (311) and the bottom outer diameter (r2) of the second member (312) may be the same. In addition, for uniform bonding, the difference between the bottom outer diameter (r1) of the first member (311) and the bottom outer diameter (r2) of the second member (312) and the bottom outer diameter (r3) of the connecting member (313) may be equal to or greater than the widthwise length of the lithium metal sheet (ML).

[0081] The first member (311) and the second member (312) may be arranged to rotate about the same rotational axis. Since the rotatable member presses the outer areas (OA) of the first separator sheet (111S) and the second separator sheet (112S) to bond them together, this may help improve the production speed.

[0082] Additionally, the center of the bottom surface of the connecting member (313) (i.e., the center of the circle) may be located on the rotational axis of the first member (311) and the second member (312). A guide roller (310) of this structure may be helpful for uniform bonding.

[0083] When the application unit (200) continuously applies the binder (B) to at least a portion of the outer area (OA) of the first separator sheet (111S) and the outer area (OA) of the second separator sheet (112S), the thickness (w1) of the first member (311) may be equal to or greater than the length (B_w1) in the width direction (TD) of the binder (B) applied to at least one of the first outer area (OA_1) of the first separator sheet (111S) and the first outer area (OA_1) of the second separator sheet (112S). The thickness (w2) of the second member (312) may be equal to or greater than the width direction (TD) length (B_w2) of the binder (B) applied to at least one of the second outer area (OA_2) of the first separator sheet (111S) and the second outer area (OA_2) of the second separator sheet (112S).

[0084] Meanwhile, the thickness (w1) of the first member (311) may be smaller than or equal to the length in the width direction (TD) of the first outer region (OA_1) of the first separator sheet (111S) and the second separator sheet (112S), and the thickness (w2) of the second member (312) may be smaller than or equal to the length in the width direction (TD) of the second outer region (OA_2) of the first separator sheet (111S) and the second separator sheet (112S). Here, each of the thickness (w1) of the first member (311) and the thickness (w2) of the second member (312) may mean the height (vertical distance between the bottoms) of the cylindrical shape.

[0085] The thickness (w3) of the connecting member (313) may be equal to or greater than the length (ML_TDw) in the width direction (TD) of the lithium metal sheet (ML). Here, the thickness (w3) of the connecting member (313) may mean the height (vertical distance between the bottoms) of the cylindrical shape.

[0086] Meanwhile, the sum of the thickness (w1) of the first member (311), the thickness (w2) of the second member (312), and the thickness (w3) of the connecting member (313) may be equal to or greater than the width direction (TD) length (111S_TDw) of the first separator sheet (111S). In addition, the width direction (TD) length of the second separator sheet (112S) may also be the same.

[0087] FIG. 14 is a plan view illustrating at least a portion of a cathode structure (400) according to an embodiment of the present application.

[0088] The electrode assembly manufacturing equipment (10) can manufacture a negative electrode structure (400) in which a first separator sheet (111S), a second separator sheet (112S), and a lithium metal sheet (ML) pass through a bonding unit (300) so that the first separator sheet (111S) and the second separator sheet (112S) are mutually bonded based on a binder (B), thereby forming a bonding area (AA) at both ends. The electrode assembly manufacturing equipment (10) may further include an additional device to improve the adhesive performance of the binder (B), and may further include, for example, at least one of a heating device and a drying device.

[0089] Meanwhile, the present application can provide a method for manufacturing an electrode assembly. The electrode assembly manufacturing method can refer to the contents of the electrode assembly manufacturing equipment (10) described above, unless there is a contradiction therebetween.

[0090] The method for manufacturing an electrode assembly may include a step of preparing a first separator sheet (111S), a second separator sheet (112S), and a lithium metal sheet (ML) in a roll form. This step may be implemented by a sheet supply unit (100) of an electrode assembly manufacturing facility (10).

[0091] The method for manufacturing an electrode assembly may include a step of applying a binder (B) to at least a portion of one of the prepared first separator sheet (111S) and second separator sheet (112S). This step may be implemented by the application unit (200) of the electrode assembly manufacturing equipment (10).

[0092] The method for manufacturing an electrode assembly may include a step of forming a negative electrode structure (400) by laminating a first separator sheet (111S) and a second separator sheet (112S) with a lithium metal sheet (ML) interposed therebetween. This step may be implemented by a laminating unit (300) of an electrode assembly manufacturing facility (10).

[0093] In the method for manufacturing an electrode assembly, the step of applying a binder (B) may include a step of applying the binder (B) to an outer area (OA) that at least partially surrounds an inner area (IA) corresponding to a lithium metal sheet (ML) in the width direction (TD) in at least one of the first separator sheet (111S) and the second separator sheet (112S) during lamination.

[0094] In the method for manufacturing an electrode assembly, a step of stacking an anode (500) on a formed cathode structure (400) and folding the cathode structure (400) in the width direction (TD) to surround the cathode (500) and sequentially stacking the cathode structure (400) and the anode (500) alternately may be further included.

[0095] The positive electrode (500) may include a positive electrode active material layer and a positive electrode current collector supporting the positive electrode active material layer. The positive electrode (500) may include a structure in which a positive electrode active material layer is formed on at least one side or both sides of the positive electrode current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder, a conductive material, and additives, as needed.

[0096] The positive electrode current collector is not particularly limited as long as it supports the positive electrode active material layer and has conductivity without causing physical and chemical changes to the composition included in the electrode assembly (50) and the battery cell, etc. For example, the positive electrode current collector may be made of copper or stainless steel surface-treated with aluminum, stainless steel, nickel, titanium, copper, palladium, calcined carbon, carbon, nickel, silver, or an aluminum-cadmium alloy. In addition, the positive electrode current collector may have fine unevenness formed on the surface, and the shape may be various, such as a film, sheet, foil, mesh, net, or foam.

[0097] The positive electrode active material may include a compound capable of reversibly intercalating and deintercalating lithium ions, sodium ions, or potassium ions. For example, the lithium, sodium, or potassium compound used as the positive electrode active material may have a layered structure, a crystal structure, or a combination thereof. In addition, the lithium compound in the present specification may be a concept encompassing all compounds in which auxiliary elements, coating elements, and doping elements are introduced or substituted around a main active element. The main active element may include, for example, one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), and aluminum (Al). The auxiliary elements, coating elements, and doping elements are elements that can improve the structural and chemical stability of the positive electrode active material by combining with the main active element, and may be distinguished according to the method of combining with the main active element. Here, combining with the main active element may include not only chemically bonding with the main active element, but also existing on the surface of the positive electrode active material or penetrating from the surface. Additionally, for example, the auxiliary elements, coating elements and doping elements may each independently include one or more selected from the group consisting of elements of Group 1, Group 2, Group 13, Group 14, Group 15, Group 16 and transition metals, excluding lithium in the periodic table.Specifically, for example, the auxiliary elements, coating elements and doping elements may each independently include one or more selected from the group consisting of sodium (Na), magnesium (Mg), calcium (Ca), yttrium (Y), titanium (Ti), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), iron (Fe), copper (Cu), silver (Ag), zinc (Zn), boron (B), gallium (Ga), carbon (C), silicon (Si), tin (Sn), strontium (Sr), barium (Ba), radium (Ra), phosphorus (P) and zirconium (Zr). For example, the cathode active material may include at least one selected from the group consisting of nickel-cobalt-manganese oxide (NCM), nickel-cobalt-aluminum oxide (NCA), nickel-cobalt-manganese-aluminum oxide (NCMA), cobalt oxide (LCO), manganese oxide (LMO), and iron phosphate (LFP) combined with lithium, sodium, or potassium.

[0098] Meanwhile, the positive electrode active material may include a sulfur compound. The sulfur compound may be an inorganic sulfur (elemental sulfur, S8), an organic sulfur compound, or Li2S. x (x is 1 or more) and carbon-sulfur polymer ((C2S y ) n , y=2.5 to 50, n=1 or more) may include at least one selected from the group consisting of. Preferably, the sulfur compound may include inorganic sulfur. When the positive electrode active material includes a sulfur compound, the electrode assembly (50) may be applied to a lithium-sulfur battery.

[0099] The binder may include a compound that can improve the internal bonding strength of the positive electrode active material layer and improve the adhesion strength of the positive electrode active material layer to the positive electrode current collector. Binders include, for example, polyvinylidene fluoride (PVDF), polyvinyl alcohol, styrene butadiene rubber (SBR), polyethylene oxide, carboxyl methyl cellulose (CMC), cellulose acetate, cellulose acetate butylate, cellulose acetate propionate, cyanoethylpullulan, cyanoethyl polyvinylalcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, polymethylmethacrylate, polybutylacrylate, It may include at least one selected from the group consisting of polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, and polyarylate.

[0100] The conductive material may include a compound that can improve the conductivity and ion or electron mobility of the positive electrode active material layer. The conductive material may include, for example, carbon-based conductive materials such as graphite, carbon black, acetylene black, Ketjen black, graphene, carbon nanotubes (CNTs), vapor-grown carbon fibers (VGCFs), and carbon fibers, and / or metal-based conductive materials including perovskite materials such as tin, tin oxide, titanium oxide, LaSrCoO3, and LaSrMnO3. The carbon nanotubes (CNTs) may include one or more selected from the group consisting of multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs), depending on the number of walls.

[0101] FIG. 15 is a plan view illustrating at least a portion of an electrode assembly (50) according to one embodiment of the present application. The electrode assembly (50) may include a positive electrode (500), a negative electrode, and a separator. Meanwhile, the electrode assembly manufacturing equipment (10) may further include a positive electrode supply device, and may manufacture the electrode assembly (50) by combining the positive electrode (500) and the negative electrode structure (400) provided from the positive electrode supply device. Here, the negative electrode structure (400) includes lithium metal, and the lithium metal may be interposed between two separators. In addition, the two separators may be formed to protrude at least partially in the width direction (TD) from the lithium metal, and at least a portion of the protruding portions of the two separators may be mutually bonded with a binder (B) with the lithium metal therebetween. This can be implemented by the electrode assembly manufacturing equipment (10) described above. That is, two separators can be manufactured by a first separator sheet (111S) and a second separator sheet (112S), and the protruding portions of the two separators can correspond to the outer areas (OA) of the first separator sheet (111S) and the second separator sheet (112S).

[0102] In addition, the electrode assembly (50) can be manufactured by, for example, zigzagging (folding) a negative electrode structure (400) manufactured in the form of a long sheet and then inserting a positive electrode (500) cut to an appropriate size into the space formed by the folding. Even if the negative electrode structure (400) includes a lithium metal sheet (ML), it can be manufactured in a curved shape due to its soft nature. On the other hand, since the positive electrode (500) is not easy to fold and is easy to cut compared to the negative electrode structure (400), it can be used by cutting it to an appropriate size as described above.

[0103] The cathode structure (400) may include a stack portion forming a laminated structure with an inserted cathode (500) and a folded portion folded as described above. The electrode assembly (50) may have a structure in which the stack portion of the cathode structure (400) and the anode (500) are alternately and sequentially laminated.

[0104] An electrode assembly (50) manufactured using electrode assembly manufacturing equipment (10) can be embedded in a case together with an electrolyte to manufacture a battery cell. In addition, a battery module, a battery pack, or an energy storage device can be manufactured using the battery cell.

[0105] The electrode assembly manufacturing equipment (10) can be widely applied to green technology fields such as electric vehicles, battery charging stations, and other battery-powered solar and wind power generation. Furthermore, the electrode assembly manufacturing equipment (10) can be applied to eco-friendly electric vehicles or hybrid vehicles, which aim to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0106] While various embodiments of the present application have been described in detail above, the scope of the present application is not limited thereto, and it will be apparent to those skilled in the art that various modifications and variations are possible without departing from the technical spirit of the present application as set forth in the claims. Furthermore, the above-described embodiments may be implemented by deleting some components, and the embodiments may be implemented in combination with each other.

[0107] [Explanation of symbols]

[0108] 10... Electrode assembly manufacturing equipment

[0109] 50... electrode assembly

[0110] 100... sheet supply section

[0111] 110... 1st sheet supply section

[0112] 111... Sheet 1-1 Supply Unit

[0113] 111S... 1st separator sheet

[0114] 112... 1-2 sheet supply section

[0115] 112S... Second separator sheet

[0116] 120... 2nd sheet supply section

[0117] ML... lithium metal sheet

[0118] 200... application area

[0119] 210... injection part

[0120] 220... storage

[0121] 230... discharge part

[0122] 300... Joint Branch

[0123] 310... Guide roller

[0124] 311... 1st absence

[0125] 312... Second absence

[0126] 313... Third Absence

[0127] 400... cathode structure

[0128] 500... bipolar

Claims

1. A sheet supply unit including a first sheet supply unit for supplying a first separator sheet and a second separator sheet and a second sheet supply unit for supplying a lithium metal sheet; An application unit that applies a binder to at least one of the first separator sheet and the second separator sheet; and It includes a bonding part that bonds the first separator sheet and the second separator sheet with the lithium metal sheet in between, Each of the first separator sheet and the second separator sheet includes an inner region corresponding to the lithium metal sheet and an outer region at least partially surrounding the outer portion of the inner region in the width direction (TD) when combined by the joint portion, A roll-to-roll electrode assembly manufacturing facility, wherein the application unit applies the binder to at least a portion of the outer area of ​​the first separator sheet and the outer area of ​​the second separator sheet.

2. In paragraph 1, An electrode assembly manufacturing facility in which the first separator sheet and the second separator sheet are mutually bonded based on the adhesive strength of the applied binder.

3. In paragraph 1, An electrode assembly manufacturing facility in which the application unit does not apply the binder to the inner area of ​​the first separator sheet and the inner area of ​​the second separator sheet.

4. In paragraph 1, Each of the outer region of the first separator sheet and the outer region of the second separator sheet includes a first outer region adjacent to a first outer boundary in the width direction (TD) of the lithium metal sheet and a second outer region adjacent to a second outer boundary in the width direction (TD) of the lithium metal sheet, The above application part Either the first outer region of the first separator sheet and the first outer region of the second separator sheet; and An electrode assembly manufacturing facility that applies the binder to either the second outer region of the first separator sheet or the second outer region of the second separator sheet.

5. In paragraph 1, The above-mentioned bonding unit bonds the first separator sheet and the second separator sheet with the lithium metal sheet interposed therebetween, such that one side of the lithium metal sheet faces the inner region of the first separator sheet and the other side of the lithium metal sheet faces the inner region of the second separator sheet. An electrode assembly manufacturing facility, wherein the application unit continuously or partially applies the binder to at least a portion of the outer area of ​​the first separator sheet and the outer area of ​​the second separator sheet.

6. In paragraph 1, The above-mentioned joint is an electrode assembly manufacturing facility including a pair of guide rollers spaced apart by a predetermined gap.

7. In paragraph 6, The above joint part, at the time of the joint, An electrode assembly manufacturing facility in which the lithium metal sheet is interposed between the first separator sheet and the second separator sheet and laminated so that the pair of guide rollers contact the first separator sheet and the second separator sheet, respectively, but do not contact the lithium metal sheet.

8. In paragraph 6, Each of the outer region of the first separator sheet and the outer region of the second separator sheet includes a first outer region adjacent to a first outer boundary in the width direction (TD) of the lithium metal sheet and a second outer region adjacent to a second outer boundary in the width direction (TD) of the lithium metal sheet, Each of the above pair of guide rollers, A first member for pressing a first outer region of each of the first separator sheet and the second separator sheet; A second member for pressing the second outer region of each of the first separator sheet and the second separator sheet; and An electrode assembly manufacturing facility comprising a connecting member connecting the first member and the second member.

9. In paragraph 8, An electrode assembly manufacturing facility in which the bottom outer diameter (r3) of the above connecting member is smaller than the bottom outer diameter (r1) of the first member and the bottom outer diameter (r2) of the second member.

10. In paragraph 8, An electrode assembly manufacturing facility, wherein the thickness (w1) of the first member is less than or equal to the width direction (TD) length of the first outer region (OA_1) of the first separator sheet and the second separator sheet, and the thickness (w2) of the second member is less than or equal to the width direction (TD) length of the second outer region (OA_2) of the first separator sheet and the second separator sheet.

11. In paragraph 8, An electrode assembly manufacturing facility in which the thickness (w3) of the above connecting member is equal to or greater than the widthwise (TD) length (ML_TDw) of the above lithium metal sheet.

12. In a method for manufacturing an electrode assembly, A step of preparing a first separator sheet, a second separator sheet, and a lithium metal sheet in a roll shape; A step of applying a binder to at least a portion of one of the first separator sheet and the second separator sheet; and A step of forming a cathode structure by laminating the first separator sheet and the second separator sheet with the lithium metal sheet interposed therebetween, The step of applying the above binder is: A method for manufacturing an electrode assembly, comprising the step of applying the binder to an outer region that at least partially surrounds an inner region corresponding to the lithium metal sheet in the width direction (TD) during lamination, in at least one of the first separator sheet and the second separator sheet.

13. In paragraph 12, A method for manufacturing an electrode assembly, further comprising the step of stacking an anode on the formed cathode structure, folding the cathode structure in the width direction to surround the anode, and sequentially stacking the cathode structure and the anode alternately.

14. In an electrode assembly including a positive electrode, a negative electrode, and a separator, The above negative electrode includes lithium metal and is sandwiched between two separators to form a negative electrode structure, The above cathode structure includes a plurality of stacked portions and a plurality of folding portions, The above electrode assembly has a structure in which a stack portion of a cathode structure and an anode are sequentially stacked alternately, The above two separators are formed to protrude at least partially in the width direction from the lithium metal, An electrode assembly, wherein at least a portion of the protruding portions of the two separators are mutually bonded with the lithium metal interposed therebetween by a binder.

15. In paragraph 14, The above positive electrode includes a positive electrode active material layer including a positive electrode active material and a positive electrode current collector supporting the positive electrode active material layer, The above positive electrode active material is an electrode assembly containing a sulfur compound.

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